open access

https://hdl.handle.net/2115/82193

Jasmonate production through chlorophyll a degradation by Stay-Green in Arabidopsis thaliana

英語

Jasmonate

2019-07

Elsevier

Journal of plant physiology

238

53-62

Leaf color change through chlorophyll degradation is a characteristic symptom of senescence. Magnesium removal from chlorophyll a is the initial step in chlorophyll a degradation, in a reaction catalyzed by Stay-Green (SGR). Arabidopsis thaliana has three SGR homologs, SGR1, SGR2, and SGR-like. When SGR1 is overexpressed, both chlorophyll a and b are degraded and leaves turn yellow. This process is visually identical to senescence, suggesting that SGR1 overexpression affects various physiological processes in plants. To examine this possibility, gene expression associated with chlorophyll metabolism and senescence was analyzed following dexamethasone-inducible SGR1 introduction into Arabidopsis. When SGR1 was overexpressed following 18 h of dexamethasone treatment, genes involved in chlorophyll degradation were upregulated, as were senescence-associated genes. These observations suggested that chlorophyll a degradation promotes senescence. As jasmonate is the plant hormone responsible for senescence and was expected to be involved in the regulation of gene expression after dexamethasone treatment, the level of jasmonoyl-isoleucine, the active form of jasmonate, was measured. The jasmonoyl-isoleucine level increased slightly after 10h of SGR1 overexpression, and this increase became significant after 18 h. These observations suggest that jasmonate is produced through chlorophyll a degradation and affects the promotion of senescence.

学術雑誌論文

Accepted Manuscript

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

©2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

0176-1617